Sildenafil (Viagra) attenuates ischemic cardiomyopathy and improves left ventricular function in mice

2008 ◽  
Vol 294 (3) ◽  
pp. H1398-H1406 ◽  
Author(s):  
Fadi N. Salloum ◽  
Antonio Abbate ◽  
Anindita Das ◽  
Jon-Erik Houser ◽  
Colin A. Mudrick ◽  
...  

We tested the hypothesis that chronic treatment with sildenafil attenuates myocardial infarction (MI)-induced heart failure. Sildenafil has potent protective effects against necrosis and apoptosis following ischemia-reperfusion in the intact heart and cardiomyocytes. ICR mice underwent MI by left anterior descending coronary artery ligation and were treated with sildenafil (0.71 mg/kg bid) or saline for 4 wk. Infarct size (IS) was measured 24 h postinfarction, and apoptosis was measured by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling. Left ventricular end-diastolic diameter (LVEDD) and fractional shortening (FS) were measured by echocardiography. Sildenafil reduced IS (40.0 ± 4.6%) compared with that in saline (69.6 ± 4.1%, P < 0.05). NG-nitro-l-arginine methyl ester, a nitric oxide synthase (NOS) inhibitor (15 mg/kg bid), blocked the protective effect of sildenafil (IS, 60.2 ± 1.6%, P < 0.05 vs. sildenafil). Western blot analysis revealed a significant increase in endothelial NOS/inducible NOS proteins 24 h post-MI after treatment with sildenafil versus saline. Apoptosis decreased from 2.4 ± 0.3% with saline to 1.2 ± 0.1% with sildenafil ( P < 0.05) on day 7 and from 2.0 ± 0.2% with saline to 1.2 ± 0.1% with sildenafil on day 28 ( P < 0.05), which was associated with an early increase in the Bcl-2-to-Bax ratio. LVEDD increased from baseline value of 3.6 ± 0.1 to 5.2 ± 0.2 and to 5.5 ± 0.1 mm on days 7 and 28, respectively, with saline ( P < 0.05) but was attenuated to 4.4 ± 0.2 and 4.4 ± 0.1 mm following sildenafil treatment on days 7 and 28, respectively ( P > 0.05 vs. baseline). FS significantly improved post-MI with sildenafil. A marked decline in cardiac hypertrophy was observed with sildenafil, which paralleled a reduction in pulmonary edema. Survival rate was lower with saline (36%) compared with sildenafil (93%, P < 0.05). Sildenafil attenuates ischemic cardiomyopathy in mice by limiting necrosis and apoptosis and by preserving left ventricular function possibly through a nitric oxide-dependent pathway.

2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Anindita Ganguly ◽  
Erika Troy ◽  
Maya Srinivas ◽  
Andrea Vecchione ◽  
Patrick Sarmiere ◽  
...  

Neuregulin-1β is essential for fetal cardiac development and adult cardiac function. Previous reports indicate that neuregulins improve left ventricular function in heart failure models, however the duration of the functional improvements with early or late initiation of neuregulin treatment has not been characterized. The present studies examine the effects of early and delayed initiation of intravenous GGF2 treatment on left ventricular (LV) function in rats with myocardial infarction (MI). Rats underwent surgically-induced MI by left anterior coronary artery ligation. Treatment with vehicle or GGF2 (2.6 mg/kg) was initiated at 2 or 16 w post-MI and continued once or twice weekly or once every two weeks for the in-life duration of the study (approximately 40 weeks). LV function was assessed echocardiographically up to once weekly for the duration of the study. Early and delayed initiation of GGF2 treatment caused sustained and significant improvement (p < 0.05) in both ejection fraction (EF) and fractional shortening (FS) in all regimens tested. The greatest improvements were seen with the once weekly dosing paradigm after early initiation (average EF (%) at 40 weeks post initiation of dosing: vehicle = 44.4 ± 6.0, n = 8 rats, vs. GGF2 = 64.7±6.1. n = 9 rats) and twice weekly dosing paradigm after delayed initiation (average EF (%) at 4 weeks post initiation of dosing: vehicle = 34.18±1.6, n = 7 rats, vs. GGF2 = 50.69±4.68, n = 7 rats). In addition, LV function improved when rats were re-challenged with GGF2 following an extended wash out period. This observation indicates potential efficacy for treatment paradigms that utilize intermittent dosing. These findings suggest that GGF2 produces sustained improvement in LV function after early or delayed initiation of treatment following MI in rats.


2013 ◽  
Vol 305 (4) ◽  
pp. H542-H550 ◽  
Author(s):  
Toshihiro Shinbo ◽  
Kenichi Kokubo ◽  
Yuri Sato ◽  
Shintaro Hagiri ◽  
Ryuji Hataishi ◽  
...  

Inhaled nitric oxide (NO) has been reported to decrease the infarct size in cardiac ischemia-reperfusion (I/R) injury. However, reactive nitrogen species (RNS) produced by NO cause myocardial dysfunction and injury. Because H2 is reported to eliminate peroxynitrite, it was expected to reduce the adverse effects of NO. In mice, left anterior descending coronary artery ligation for 60 min followed by reperfusion was performed with inhaled NO [80 parts per million (ppm)], H2 (2%), or NO + H2, starting 5 min before reperfusion for 35 min. After 24 h, left ventricular function, infarct size, and area at risk (AAR) were assessed. Oxidative stress associated with reactive oxygen species (ROS) was evaluated by staining for 8-hydroxy-2′-deoxyguanosine and 4-hydroxy-2-nonenal, that associated with RNS by staining for nitrotyrosine, and neutrophil infiltration by staining for granulocyte receptor-1. The infarct size/AAR decreased with breathing NO or H2 alone. NO inhalation plus H2 reduced the infarct size/AAR, with significant interaction between the two, reducing ROS and neutrophil infiltration, and improved the cardiac function to normal levels. Although nitrotyrosine staining was prominent after NO inhalation alone, it was eliminated after breathing a mixture of H2 with NO. Preconditioning with NO significantly reduced the infarct size/AAR, but not preconditioning with H2. In conclusion, breathing NO + H2 during I/R reduced the infarct size and maintained cardiac function, and reduced the generation of myocardial nitrotyrosine associated with NO inhalation. Administration of NO + H2 gases for inhalation may be useful for planned coronary interventions or for the treatment of I/R injury.


Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Ana Carolina M Omoto ◽  
Fábio N Gava ◽  
Mauro de Oliveira ◽  
Carlos A Silva ◽  
Rubens Fazan ◽  
...  

Myocardium infarction (MI) elicited by coronary artery ligation (CAL) is commonly used to induce chronic heart failure (HF) in rats. However, CAL shows high mortality rates. Given that ischemia-reperfusion (IR) may cause the development of HF, this approach may be useful for obtaining a model of HF with low mortality rates. Therefore, it was compared the model of CAL vs. IR in rats, evaluating the mortality and cardiac morphological and functional aspects. The IR consisted of 30 minutes of cardiac ischemia. Wistar rats were assigned into three groups: CAL: n=18; IR: n=7; SHAM (fictitious IR): n=7. After four weeks of CAL, the subjects were evaluated by echocardiography and ventriculography as well. The statistical analysis consisted of ANOVA combined with Tukey’s posthoc test (p<0.05). There were no deaths in the IR and SHAM groups, whereas in the CAL group the mortality rate was 33.33% (6 out of 18). In the CAL group echocardiography showed increased left ventricular (LV) cavity during systole (8.3 ± 1mm) and diastole (10.5 ± 1mm); decreased LV free wall during systole (1.4 ± 0.5 mm); increased left atrium/aorta (2.3 ± 0.4) ratio. These changes were not significant in IR (4.8 ± 0.5mm, 7.6 ± 0.6mm, 2.6 ± 0.3 mm, 1.6 ± 0.2) and SHAM (4.6 ± 0.6 mm, 7.7 ± 0.8mm, 2.8 ± 0.4mm, 1.5 ± 0.2) groups. There was also the reduction in the ejection fraction in the CAL group (41 ± 12 %) when compared with IR (65 ± 9%) and SHAM (69 ± 7%) groups. The tissue Doppler analysis from the lateral mitral annulus showed reduction in E′ in CAL (-29 ± 8 mm/s) and IR (-31± 9 mm/s) groups when compared with the SHAM (-48 ± 11 mm/s) group. The ventriculography in the CAL group showed smaller maximum dP/dt (6519 ± 1062) and greater end-diastolic pressure (33 ± 8 mmHg) when compared with IR (8716 ± 756 mmHg/s; 9 ± 9 mmHg) and SHAM (7989 ± 1230 mmHg/s; 9 ± 7 mmHg) groups. The CAL group presented transmural infarct size of 40% of the left ventricular wall, measured under histopathological examination. In conclusion, IR for 30 minutes caused only small changes in LV diastolic function, assessed by tissue Doppler; however, the IR was not effective for promoting HF, as observed with CAL. Thus, it is possible that prolonged IR is necessary for promoting significant HF in rats.


2004 ◽  
Vol 116 (2) ◽  
pp. 187-196 ◽  
Author(s):  
Pavlos Moustakidis ◽  
Brian P. Cupps ◽  
Benjamin J. Pomerantz ◽  
Randall P. Scheri ◽  
Hersh S. Maniar ◽  
...  

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Jordan J Lancaster ◽  
Elizabeth Juneman ◽  
Pablo Sanchez ◽  
Kyle Weigand ◽  
Talal Moukabary ◽  
...  

Background: Chronic Heart Failure (CHF) is the leading cause of hospital readmissions in the United States. It may result from systolic or diastolic dysfunction, which often coexists. Here we report the effects of delivering human induced pluripotent stem cells derived cardiomyocytes (hiPSC-CMs) via a bioengineered patch on left ventricular function in rats with CHF. Methods: Adult male Sprague-Dawley rats underwent left coronary artery ligation and were randomized to Sham, CHF, and hiPSC-CM patch. High purity human hiPSC-CMs were obtained from Cellular Dynamics International, seeded and co-cultured onto a vicryl matrix embedded with human dermal fibroblasts. Echocardiography was performed at 3 and 6 weeks post-randomization. Hemodynamic pressure measurements were performed at 6 weeks post-ligation with Millar solid state micromanometer catheters. Open chest Electrophysiologic (EP) mapping was performed at 6 weeks post ligation. Results: Patches constructed with hiPSC-CMs displayed synchronized and spontaneous contractions within 48hrs of culture which developed in robustness over time. At maximal robustness, contractions were visualized across the full thickness of the construct. Contractions were recorded at 36+5 beats BPM. Three weeks after implantation, the hiPSC-CM patch decreased LV EDP (45%), Tau (29%), E/e’ (23%) and increased, EF (14%), e’ (20%), and e’/a’ (36%) versus CHF. EP studies show electro-mechanical coupling between the patch and the native myocardium with normal activation through the patch and increases (P<0.05) voltage amplitude in CHF versus hiPSC-CM patch treated rats (1±0.5 mV vs 6±1.5mV). Conclusion: Cardiac patch implantation with human iPSC derived cardiomyocytes is an effective and feasible method of treating CHF with improvements in systolic function, diastolic function, and electro-mechanical coupling in rats with CHF.


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